This report documents the development of monthly and seasonal ADT factors for performing estimating AADT's. lt appears that seasonal factors can estimate AADT as well as monthly factors, and it is recommended that seasonal factors be used.

Hourly distribution factors were also developed in this study. These are to be used in life-cycle costing analyses for calculating queue lengths in estimating user delay costs.

In this study, a comparison was made between automatic vehicle classification counters and manual counts. For the type of equipment used, automobiles were overestimated, pickup trucks were underestimated, and Type 9's were also underestimated.

Lane distribution factors were developed in this study. The factors were developed as a function of ADT and percent of trucks.

Report Date


Report Number


Digital Object Identifier



The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Cabinet, nor the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names and trade names are for identification purposes and are not to be considered as endorsements.